The European Geostationary Navigation Overlay Service (EGNOS), Europe’s first venture into satellite navigation, improves the open public service offered by the USA’s Global Positioning System (GPS).

EGNOS makes GPS suitable for safety critical applications such as flying aircraft or navigating ships through narrow channels (see the EGNOS video for more information).

Known as a satellite-based augmentation system (SBAS), EGNOS provides both correction and integrity information about the GPS system, delivering opportunities for Europeans to use the more accurate positioning data for improving existing services or developing a wide range of new services.

Correction data

As a satellite navigation augmentation system, EGNOS improves the accuracy of GPS by providing a positioning accuracy to within three metres. By comparison, someone using a GPS receiver without EGNOS can only be sure of their position to within 17 metres.

Integrity message

EGNOS also provides verification of the system’s integrity, which relates to the trust that can be placed in the correctness of the location information supplied by the navigation system. In addition, it provides timely warnings when the system or its data should not be used for navigation. Integrity is a feature which meets the demands of safety-critical applications in sectors such as aviation and maritime, where lives might be endangered if the location signals are incorrect.


EGNOS’ infrastructure consists of three geostationary satellites over Europe and a network of ground stations. Since it is based on GPS, the EGNOS signal does not require major changes to receivers. Today, many GPS receivers available on the market are also EGNOS enabled.

The development of EGNOS arose from a tripartite agreement between the European Space Agency (ESA), the European Commission (EC) and Eurocontrol, the European Organisation for the Safety of Air Navigation. It is the precursor to Galileo, the global navigation satellite system (GNSS) being developed by the European Union. EGNOS and Galileo are now part of Europe’s GNSS programmes managed by the European Commission.

EGNOS Services

EGNOS is offering three services. These are:

  • Open Service: The service is provided free of charge without any guarantee or resulting liability. It is open for use to anyone with an EGNOS-enabled satellite navigation receiver. This can be any receiver compatible with satellite-based augmentation systems. The Open Service was launched on 1 October 2009.
  • Safety-of-life Service: EGNOS provides a valuable integrity message warning the user of any malfunction of the GPS signal within six seconds. This integrity message is essential when satellite navigation is used for applications where lives are at stake. The EGNOS Safety-of-life Service was certified for civil aviation in 2011.
  • Commercial Service: EGNOS provides a terrestrial commercial data service called the EGNOS Data Access Service (EDAS). EDAS disseminates EGNOS data in real time and is the single point of access for the data collected and generated by the EGNOS infrastructure.


As EGNOS provides an unprecedented level of accuracy and reliability, new services can be developed – including for safety-critical applications – in a wide range of market segments.

These include:

  • Aviation: EGNOS provides the accuracy needed to help guide pilots both en route and for runway approaches, leading to increased safety in the air for passengers and more efficiency and savings for companies. EGNOS also allows larger passenger aircraft to land at regional airports, which may not have previously been equipped to handle them. Helicopter operations such as offshore, mountain rescue and emergency medical services can dramatically benefit from EGNOS. In particular, EGNOS enhances vertical precision and integrity improving safety, accessibility and efficiency for operators, pilots and helipads across Europe. It leads to a substantial reduction in the decision height, making helipads accessible in poor weather conditions, which makes a significant difference for medical and emergency operations.
  • Road: EGNOS is a key tool for better managing land transport in Europe, increasing both capacity and safety, whether by road or rail. Improved positioning accuracy helps companies enhance their transport logistical operations. Public operations, such as police and emergency services, can use EGNOS to improve the speed of their responses in critical situations.
  • Agriculture: Precision agriculture refers to the use of satellite navigation sensors, aerial images, and other tools to determine optimum sowing density, fertiliser cover and other inputs. The techniques allow farmers to save money, reduce their impact on the environment and increase crop yields. EGNOS provides an affordable precision solution for farmers.
  • Mapping: Now EGNOS can contribute in growing the use of GNSS in real time mapping solutions by providing free accuracy that is widely available. For many mapping applications the meter level accuracy provided by EGNOS is sufficient. Applications such as thematic mapping for small and medium municipalities, forestry and park management and also for utility infrastructures can benefit from EGNOS.
  • Maritime: EGNOS will improve navigation at sea and of inland waterways. It can be used for port operations, traffic control, casualty analysis, offshore exploration and fisheries management.
  • Location-Based Services (LBS): Location-based technologies and services embedded in vehicle telematics, personal navigation devices and mobile phones will benefit from the improved accuracy provided by EGNOS. Such precision, to within three metres, will be used for services such as pedestrian applications, locating nearby friends or mobile social networking.